This document defines and provides information about mass, volume, and density. It explains that mass is the amount of matter in an object and can be measured in kilograms or grams using a scale or balance. Volume is the amount of space an object takes up and can be found by multiplying length, width, and height, with units of liters or milliliters. Density is the ratio of an object's mass to its volume, calculated by dividing mass by volume. Examples are given for calculating the volume and density of objects using different measurements.